Mold for concrete C-profiles including a removeable core

ABSTRACT

A mold for concrete beams witn an upper web and a pair of depending lateral flanges, forming a C-profile, comprises an elongate outer form with two parallel walls rising from a base and a box-shaped inner form of trapezoidal cross-section resting on that base, the sides of the inner form being spaced from the walls of the outer form to define clearances for the beam flanges. The sides of the inner form carry a pair of substantially horizontal external ledges contacting the outer form in the assembled state of the mold; after the concrete has been poured, but before complete hardening, the molded beam is withdrawn together with the inner form, whose ledges support the beam flanges, from the outer form to allow use of the latter for further molding operations.

United States Patent Haller et a1.

MOLD FOR CONCRETE C-PROFILES INCLUDING A REMOVEABLE CORE Inventors: HansHaller; Erwin Wendl, both of Nibelungengasse 40, Graz, Austria Notice:The portion of the term of this patent subsequent to Oct. 23, 1990,

has been disclaimed.

Filed: July 20, 1973 Appl. No.: 381,037

Related U.S. Application Data Continuation-impart of Ser. No. 75851,Sept. 28, 1970, Pat. No. 3,767,153.

U.S. Cl. 425/432; 249/63; 249/79; 249/142; 249/158 Int. Cl. B28B l/08Field of Search 425/432, 456; 249/50, 63, 249/79, 81, 142,144,156,158,160,

168-l72, 175, 177; 264/D1G. 43, 33, 34,

References Cited UNITED STATES PATENTS 2,836,875 6/1958 Chandler et a1.249/180 3,385,554 5/1968 Anderson 249/165 3,441,243 4/1969 Walz 249/813.539,]46 11/1970 Smith 249/63 3,767,153 10/1973 Haller et a1. 249/18FOREIGN PATENTS OR APPLICATIONS 683,087 11/1952 United Kingdom 425/443Primary Examiner-R0bert D. Baldwin Assistant Examiner-John MCQuadeAttorney, Agent, or Firm-Karl F. Ross; Herbert Dubno [57] ABSTRACT Amold for concrete beams witn an upper web and a pair of dependinglateral flanges, forming a C-profile. comprises an elongate outer formwith two parallel walls rising from a base and a box-shaped inner formof trapezoidal cross-section resting on that base, the sides of theinner form being spaced from the walls of the outer form to defineclearances for the beam flanges. The sides of the inner form carry apair of substantially horizontal external ledges contacting the outerform in the assembled state of the mold, after the concrete has beenpoured, but before complete hardening, the molded beam is withdrawntogether with the inner form, whose ledges support the beam flanges,from the outer form to allow use of the latter for further moldingoperations.

10 Claims, 6 Drawing Figures US. Patent Nov. 25, 1975 3,922,135

f Hi

VIBEATORS 5 MOLD FOR CONCRETE C-PROFILES INCLUDING A REMOVEABLE CORECROSS-REFERENCE TO RELATED APPLICATION This application is acontinuation-in-part of our copending application Ser. No. 75,851 filedSept. 28, 1970, now US. Pat. No. 3,767,153.

FIELD OF THE INVENTION The present invention relates to a mold forcasting C-profiles of concrete, for incorporation in a roof, platform,deck or similar structure to be made up from a plurality of precastelements of this nature.

BACKGROUND OF THE INVENTION The individual precasting of beams, planksor other elongate components of a larger concrete structure, to beassembled at a building site, has well-recognized advantages intransportation and handling over the casting of an entire structureeither at the factory or on location. However, conventional technique insuch cases requires the provision of a number of identical molds ifseveral concrete bodies are to be cast simultaneously, i.e. if thepouring of the concrete for one body is to commence before thepreviously cast body has completely hardened.

In our copending application identified above, there has been discloseda method of producing such profiles in staggered succession with the aidof a mold comprising an outer form and several interchangeable innerforms, the outer form defining with an associated inner form a space forthe casting of a C-profile with an upper web and a pair, of dependinglateral flanges which can be bodily removed from the outer form, upon apartial hardening of the concrete, together with the inner form wherebythe outer form becomes available for the casting of a new profile withthe aid of another inner form. The profile is allowed to set completelywhile remaining supported by the associated inner form, the number ofavailable inner forms thus determining the number of profiles that canharden simultaneously.

OBJECTS OF THE INVENTION The general object of our present invention isto provide an improved composite mold to'be used for this purpose.

A more particular object is to provide a mold of this description whoseinner form is robust enough to maintain the shape of the cast profileduring the setting thereof, yet is of simple structure enabling suchinner forms to be inexpensively produced in the number required for agiven production schedule.

SUMMARY OF THE INVENTION The outer form of a mold according to ourinvention includes a pair of substantially parallel walls rising from abase, these walls being separated from the sides of the inner form byclearances accommodating the lateral flanges of a C-profile to bemolded. The inner mold, which is removably seated on the base and islower than the walls of the outer form, is provided with substantiallyhorizontal external ledges extending from its sides and contacting theconfronting walls of the outer form, thereby spanning theintervening-clearances. In order to enable the inner form to be liftedout of the outer form, together with a partially set c-profile havingits 5 may be constituted, advantageously, by the extremities of one ormore conduits for a curing fluid (e.g. steam) which traverse the innerform and project endwise therefrom. At least one pair of longitudinallyspaced end members extend between the two forms acrossthe interveningclearances and rise above the inner form to the level of the walls ofthe outer form; these end members, or at least one of them, may belongitudinally dis-' placeable in accordance with the desired length ofa profile to be molded and may be fastenable to either or both outerwalls in a selected position.

According to a more specific feature of our invention, the inner form isgenerally box-shaped and has an upwardly converging, substantiallytrapezoidal crosssection giving it a slight draft to facilitate thedetachment of the fully hardened profile from its sides.. We have found,surprisingly enough, that the extraction of the inner form with thepartially hardened concrete body from the outer form creates noparticular difficulties even if the outer walls are perfectly paralleland vertical.

A particularly sturdy inner form of a mold according to our inventionhas the shape of a prismatic tube with preferably solid top and bottomplates as well as end BRIEF DESCRIPTION OF THE DRAWING The above andother features of our invention will now be describedin greater detailwith reference to the accompanying drawing in which:

FIG. 1 is a side-elevational view of a mold for producing elongateconcrete bodies, specifically C-profiles, in accordance with ourinvention;

FIG. 2 is a top view of the mold shown in FIG. 1;

FIG. 3 is a cross-sectional view taken on the line III- III of FIG. 2but drawn to a larger scale;

FIG. 4 is an elevational view of a template serving as an end memberfor. the mold of FIGS. 1-3;

FIG. 5 is a side-elevational view of the template shown in FIG. 4; and

FIG. 6- is a perspective view of an inner form representing one of thecomponents of the mold.

SPECIFIC DESCRIPTION The mold shown in the drawing consists essentiallyof an outer form 2 and an inner form 3, the latter being removablyseated on a set of transverse beams 1 constituting the base of the outerform 2. This outer form further comprises a pair of upstanding walls 2a,2b rigidly connected with the beams l by brackets 42 with the aid ofscrews 14 and 41. The beams 1 are anchored by stirrups In to afoundation 20 (e.g. of concrete), the threaded tips of the stirrupspassing through slots in the beam flanges whereby the base can belimitedly shifted laterally; centering screws 7, passing through anchors3 7a, serve to maintain the base in the porper position on thefoundation.

The inner form 3 is basically a prismatic tube with a slightly convextop 3a, sides 3b, 3c and a bottom 3d as well as end plates 10. The top,sides and bottom are assumed to consist of solid sheet material, e.g.steel, whereas the end plates are perforated to give passage toextremities 9a, 9b of a pair of longitudinally extending bars 9 whichcan be gripped by hooks of a crane for the purpose of lifting the form 3off the base 1 or returning it to that base between the walls 2a, 2b ofthe outer form 2. The bars 9 are shown to be tubular so as to serve asconduits for the admission of a curing fluid, such as steam or hot air,into the interior of form 3; the curing fluid may escape into the formproper through orifices (not shown) provided in one of the pipes 9 andmay be exhausted by way of similar orifices in the other pipe.

The clearances between walls 2a, 2b and sides 3b, 3c are automaticallymaintained by lateral bottom ledges 3e which are integral with thebox-shaped body of form 3 and which contact these walls at their roots.Furthermore, as shown in FIG. 3, the sides 3b and 3c of form 3 may beprovided with ancillary ledges 4 which are adjustably mounted thereon toform a false bottom above the fixed ledges 3e. Since the form 3 has agenerally trapezoidal cross-section, with the sides 3b and convergingupwardly, the width of the ancillary ledges 4 should be slightly largerthan that of bottom ledges 3e; the ledges 4 may be elevated to a desiredlevel, depending on the height of the flanges of a concrete profile tobe cast in the mold, with screws 14 loosened to permit the walls 2a and2b to be moved into abutting relationship with ledges 4 so that theflanges-forming clearances dedefined by these walls and by sides 3b and3c are practically completely closed at the bottom. in order tofacilitate such adjustment, screws 14 pass through slots in brackets 42or in the upper flanges of l-beams 1.

If the height of the concrete profile is to correspond to that of theouter mold 2, the adjustable ledges 4 may be detached so that theflanges of profile 40 come to rest directly on the fixed ledges 3e.

The length of the profile is determined by two templates 5 inserted atselected locations in the channel between walls 2a and 2b, each of thesetemplates comprising a horizontal bar 5a and a pair of legs 5b, 51'. Bar50 hugs the top 3a of inner form 3 whereas legs 5b and 50 act aspartitions in the clearances between the two nested forms. Naturally,templates 5 with legs of different height will be required for differentvertical positions of ancillary ledges 4 if such ledges are being used.

As best shown in FIGS. 4 and 5, each template 5 is integral with aC-clamp 11 including an arm 110 which overhangs its leg 5c and definestherewith a slot 1 1b receiving the top of wall 2b of the outer form 2upon operative insertion of the template in a selected position. Screwsl2 serve to fasten the template to wall 2b in order to immobilize itwith reference to the mold. The templates, therefore, have theadditional function of holding the inner mold 3 in place on the base 1the outer mold 2. Prior to extraction of mold 3 together with thepartially hardened concrete profile 40, screws 12 must be loosened sothat templates 5 riding the form 3 can be withdrawn together with thatform and the concrete profile. Upon such extraction, form 3 with itstemplates and the cast body can be stored at some convenient locationpending final handling of that body.

4 Prior to such hardening, as described in our copending application andpatent, the concrete body may be further shaped (e.g. manually) withformations of recesses, cutouts or the like therein. Also, steam or thelike may be circulated through the form 3 via pipes 9 as described aboveto accelerate the hardening process.

Metal reinforcements and/or prestressing cables may pass through holes13 in templates 5 for imbedding in the concrete profile 40. The top ofthe casting may be made level with the edges of form 2, or slightlylower than these edges, by passing over it with a strike bar as shownand described in our copending application and patent.

in order to manufacture two or more C-proflles of reduced length on asingle inner form, three or more templates 5 can be inserted into themold at suitable locations. As seen in FIG. 5, the templates may havedownwardly converging front and rear surfaces to simplify the task ofextracting them from between two adjoining concrete bodies formed inthis manner. A bracket 6, carried by the clamp 11, resiliently bearsupon the upper edge of wall 2b to prevent canting of the template.

Vibrators 8 are mounted at longitudinally spaced locations on the twoparallel walls 20, 2b of outer form 2 and are set in operation duringthe pouring of the concrete into the channel between these walls,thereby insuring a uniformly dense deposit. The boundaries of thischannel, i.e. the confronting surfaces of walls 20, 2b and the outersurfaces of top 3a and sides 3b, 3c of form 3 as well as the upper facesof ledges 3e and 4, may be provided with low-adhesion castings foreasier separation from the concrete body; templates 5 can be similarlycoated.

The unitary construction of inner form 3 (except for the optionallyprovided adjustable ledges 4 thereof) gives that form the compressivestrength necessary for sustaining the stresses to which the form issubjected both within the mold and thereafter during the setting of theenveloping concrete body. It is not absolutely essential, however, thatthe bottom 3d of the form 3 be a continuous plate", thus, a series oftransverse braces will suffice in many instances. Also, as likewisedescribed in our copending application and patent, the form could becast in one piece as a solid concrete beam.

1 claim:

1. A mold for casting a C-profile of concrete, comprising: an outer formincluding a base and a pair of substantially parallel lateral wallsrising fixedly from said base; an inner form lower than said wallsremovably seated on said base between said walls, said inner form havingsides separated from said walls by ciearances accommodating a pair oflateral flanges of a C- profile to be molded, said sides being providedwith substantially horizontal external ledges spanning said clearancesand contacting said walls; at least one pair of longitudinally spacedend members extending across said clearances longitudinally, subdividingsame between said forms and resting on said ledges while rising abovesaid inner form to the level of said walls; and anchor means on saidinner form enabling the same to be lifted out of said outer formtogether with said end members and with a molded C-profile havinglateral flanges supported by said ledges.

2. A mold as defined in claim 1 wherein said base comprises amultiplicity of spaced-apart cross-beams rigid with said walls.

3. A mold as defined in claim 1 wherein said inner form has an upwardlyconverging, substantially trapezoidal cross-section.

4. A mold as defined in claim 1 wherein said inner form has a top and abottom complementing said sides to a horizontal tube of polygonalcross-section.

5. A mold as defined in claim 4 wherein said tube has substantiallyclosed ends provided with said anchor means.

6. A mold as defined in claim 4 wherein said ledges are at the level ofthe bottom of said tube.

7. A mold as defined in claim 1 wherein at least one of said end membersis longitudinally shiftable along 6 said inner form and is provided withfastening means for releasably securing it in a selected position to atleast one of said walls.

8. A mold as defined in claim 1, further comprising vibrator meansmounted on each of said walls.

' 9. A mold as defined in claim 1, further comprising conduit meanspassing through said inner form for conducting a curing fluidtherethrough.

10. A mold as defined in claim 9 wherein said conduit means is providedwith at least one pair of extremities projecting end-wise from saidinner form, said extremities forming part of said anchor means.

1. A mold for casting a C-profile of concrete, comprising: an outer formincluding a base and a pair of substantially parallel lateral wallsrising fixedly from said base; an inner form lower than said wallsremovably seated on said base between said walls, said inner form havingsides separated from said walls by clearances accommodating a pair oflateral flanges of a C-profile to be molded, said sides being providedwith substantially horizontal external ledges spanning said clearancesand contacting said walls; at least one pair of longitudinally spacedend members extending across said clearances longitudinally, subdividingsame between said forms and resting on said ledges while rising abovesaid inner form to the level of said walls; and anchor means on saidinner form enabling the same to be lifted out of said outer formtogether with said end members and with a molded C-profile havinglateral flanges supported by said ledges.
 2. A mold as defined in claim1 wherein said base comprises a multiplicity of spaced-apart cross-beamsrigid with said walls.
 3. A mold as defined in claim 1 wherein saidinner form has an upwardly converging, substantially trapezoidalcross-section.
 4. A mold as defined in claim 1 wherein said inner formhas a top and a bottom complementing said sides to a horizontal tube ofpolygonal cross-section.
 5. A mold as defined in claim 4 wherein saidtube has substantially closed ends provided with said anchor means.
 6. Amold as defined in claim 4 wherein said ledges are at the level of thebottom of said tube.
 7. A mold as defined in claim 1 wherein at leastone of said end members is longitudinally shiftable along said innerform and is provided with fastening means for releasably securIng it ina selected position to at least one of said walls.
 8. A mold as definedin claim 1, further comprising vibrator means mounted on each of saidwalls.
 9. A mold as defined in claim 1, further comprising conduit meanspassing through said inner form for conducting a curing fluidtherethrough.
 10. A mold as defined in claim 9 wherein said conduitmeans is provided with at least one pair of extremities projectingend-wise from said inner form, said extremities forming part of saidanchor means.